Foot operated cutting device

ABSTRACT

A foot operated cutting device used to perform pruning, shearing, trimming, and similar operations includes a cutting head provided with a spring biased blade cooperating with a jaw, an actuating mechanism in a housing coupled to a foot actuating device. The foot operated cutting device generates power from a force input supplied by a user to the foot actuator.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.09/281,524, filed on Mar. 30, 1999 and issued as U.S. Pat. No. 6,101,725on Aug. 15, 2000.

BACKGROUND OF THE INVENTION

Many cutting devices used in gardening include a pair of handle sectionswhich are operated by a hand, and a cutting head attached to the handlesections. The cutting head performs either a scissors action or ananvil-type lopping action. Cutting devices of this type include handdriven pruners, hedge shears, grass shears, and the like.

Hand driven devices such as those mentioned above, provide severedrawbacks, especially during extended work periods. Even during times oflimited work periods, hand driven cutting devices are limited by thepower of the hand itself. In periods of extended work, hand drivencutting devices require that the hand and arm be held in difficult andawkward positions in order to extend reach and to cut at a variety ofangles. Placing the hand and arm in awkward positions leads to fatigueof the hand and arm muscles and in the long term can produce problemswith tendons, especially in the so-called carpal tunnel areas of thehand and wrist, and further strenuous hand operation may cause blistersof the hand.

For professional applications, a variety of powered devices have beendeveloped. For example electric, pneumatic, hydraulic, and gas-poweredcutting devices have been developed and used. These devices, althoughnot requiring cutting input to be provided by the hand, still have anumber of drawbacks. These drawbacks include high price, due to thecomplexity of the devices and high weight, due to the power plants forthe devices. For example, a battery driven unit requires a heavy pack ofbatteries that must be carried on an operator's back. The weight ofthese battery units may be in the range of 5-10 kilograms, or more.Therefore, although powered devices have as their goal, less fatigue foran operator, because the cutting power is provided by an electric,pneumatic, hydraulic, or gas powered device, fatigue is still producedbecause an operator is still burdened with the weight of these deviceswhile working in the garden or field. Furthermore, the complexity ofthese powered devices typically produces bulkiness or awkwardness makingit both difficult to transport and difficult to position the cuttinghead at the proper angle to produce the desired cutting result.

There is a need and desire for a foot driven cutting device that has areduced amount of complexity when compared with other powered cuttingdevices.

There is also a need and desire for a foot driven cutting device forwhich the legs of an operator provide the cutting force that istransmitted to a cutting head and the hand of the operator is used tocontrol the cutting head.

There is also a need and desire for a foot operated cutting devices thatdoes not require any accessories beyond a foot actuator, a cuttingdevice, and a force transmitter connecting the foot actuator and thecutting device. Further still, there is a need and desire for a footactuated cutting device that provides less fatigue for an operator whencompared with traditional hand driven cutting devices.

SUMMARY OF THE INVENTION

The invention relates to a cutting device including a cutting head, ahousing supporting the cutting head, and an actuation mechanism. Theactuation mechanism includes a foot actuator, and a flexible forcetransmitter coupled to the foot actuator on a first end and coupled tothe housing on a second end. The actuation mechanism transmits a forceinput from the foot actuator through the flexible force transmitter andto the cutting head thereby producing a cutting action.

The invention further relates to a cutting device including a cuttinghead, a foot actuator, a flexible force transmitter, and a housing. Theflexible force transmitter is coupled to the foot actuator on a firstend, and the housing supports the cutting head and includes a drivemechanism. The drive mechanism couples the flexible force transmitter tothe blade. The flexible force transmitter receives a force input fromthe foot actuator and provides a force, through the flexible forcetransmitter, to the blade.

The invention still further relates to a cutting device including acutting head, a foot actuator, a housing, and a hydraulic hose. The footactuator has a first hydraulic cylinder coupled thereto. The housingsupports the cutting head and a second hydraulic cylinder. The secondhydraulic cylinder is coupled to the cutting head. The hydraulic hose iscoupled to the first hydraulic cylinder on a first end and coupled tothe second hydraulic cylinder on a second end, the hydraulic hosecommunicates hydraulic fluid between the first and second hydrauliccylinders. The foot actuator receives a force input, the force input istransmitted to the first hydraulic cylinder thereby causing hydraulicfluid to flow through the hydraulic hose and causing movement in thesecond hydraulic cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the present invention willhereinafter be described in conjunction with the appended drawings,wherein like reference numerals denote like elements and;

FIG. 1 depicts an operator using a foot operated cutting device;

FIG. 2 is a partial cut away view of a cutting head and an elevationalview of a foot actuator, the foot actuator being in a non-actuatedposition and the jaws of the cutting device being open;

FIG. 3 depicts the same cutting device and foot actuator as depicted inFIG. 2 but having the foot actuator in an actuated state and depictingthe cutting head in a closed state;

FIG. 4 depicts the reconfigurability of the cutting device capable ofhaving multiple cutting heads and an extension handle attached thereto;

FIGS. 5A and 5B depict an operator using a foot operated cutting devicehaving an extension handle;

FIG. 6A depicts a foot actuator that is attachable to a shoe, the footactuator being in a locked stated;

FIG. 6B depicts the foot actuator of FIG. 6A in an actuated but unlockedstate;

FIG. 6C depicts the foot actuator of FIG. 6A in an unlocked andnon-actuated state;

FIG. 7 depicts a foot operated cutting device having a hydrauliccylinder at the foot actuator and a hydraulic cylinder at the cuttinghead.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to cutting tools such as pruners, headshears, or grass shears. However, while the invention as describedherein will often be referred to as a pruner, those skilled in the artwill appreciate that the mechanisms described herein and theirprinciples of operation can be broadly applied to a wide variety ofother cutting implements generally. Referring to FIG. 1, an operator 10is depicted using a foot operated pruner 20. Foot operated pruner 20includes a cutting head 25, a flexible force transmitter 30, and a footactuator 35. Power is transmitted to the cutting head from the legmuscles 40 of operator 10 as operator 10 presses his heel 45 down onactuator 35. The force generated by leg muscles 40 is transmittedthrough flexible force transmitter 30 to the cutting head 25. It shouldbe noted that although operator 10 is shown using the foot operatedpruner 20 with his heel 45, other portions of the body could be used toprovide force to foot actuator 35 including, but not limited to, theoperator's toe 46.

In a preferred embodiment of the present invention, flexible forcetransmitter 30 may be routed over the shoulder 11 of operator 10(depicted in FIGS. 1, 5A, and 5B) to minimize interference with objectsthat may be close to operator 10, such as twigs or branches and thelike. As depicted in FIG. 1, flexible force transmitter 30 hassufficient slack so that an arm 13 of operator 10 may be in amultiplicity of positions (one alternative position is depicted byphantom lines in FIG. 1) to place cutting head 25 at different cuttingpositions.

Referring now to FIG. 2, foot operated pruner 20 is depicted in anon-actuated or open state. In other words, foot actuator 35 is notbeing actuated by heel 45 therefore, cutting head 25 is biased in anopen position by a biasing spring 50. Cutting head 25 includes a blade52 pivotally coupled to a jaw 54 at a pin 56. Blade 52 and jaw 54 createa bight 53 designed to receive a workpiece 51, such as twigs orbranches. Blade 56 is pivotally coupled to a connecting link 58 at a pin60 and jaw 54 is coupled to a housing 62 at a jaw base 64. Connectinglink 58 is pivotally coupled to a rod 66 at a pin 68. Rod 66 isconstrained to slide substantially linearly within housing 62. Thelinear travel of rod 66 is limited by a stop 70 that is coupled to rod66 and engages housing 62 when cutting device 25 is in a fully openposition as depicted in FIG. 2. Rod 66 is also coupled to a cable 72,cable 72 transmits the force from foot actuator 35 to cutting head 25.Biasing spring 50 forces rod 66 and therefore blade 52 into the fullyopen position depicted in FIG. 2 when there is little or no force beingtransmitted through cable 72.

Cable 72 slides within a sheath 74, sheath 74 extending between housing62 and foot actuator 35. Cable 72 and sheath 74 make up flexible forcetransmitter 30. Foot actuator 35 includes a base 76 and a tread 78pivotally coupled to base 76 at a pin 80. Sheath 74 is coupled to base76 and cable 72 is coupled to tread 78 so that when leg muscles 40 ofoperator 10 produce a force on heel 45, as depicted in FIG. 3, therotational movement of tread 78 causes cable 72 to be extended fromsheath 74 at base 76. Therefore, cable 72 transmits a force producedfrom heel 45 through cable 72 to rod 66. As depicted in FIG. 3, rod 66travels in a direction shown by arrow 82. As rod 66 is pulled indirection 82, connecting link 58 causes blade 52 to rotate about pin 56and thereby causing cutting head 25 to come to a closed position asdepicted in FIG. 3 whereby blade 52 overlaps or contacts jaw 54. Asdepicted in FIG. 3, with bight 53 closed, workpiece 51 has been severed.Because leg muscles 40 are capable of supplying a much greater force tofoot actuator 35 than the force that could be supplied by an operator'shand to the handles of a conventional cutting device, foot operatedpruner 20 is able to sever heavier branches than can be severed using aconventional pruner.

As rod 66 is moved in direction 82, biasing spring 50 is compressed asdepicted in FIG. 3 thereby storing potential energy. Potential energystored in biasing spring 50 may be used later to return blade 52 to theopen position, as depicted in FIG. 2.

As depicted in FIG. 1, operator 10 holds cutting head 25 in his hand 12.As depicted in FIGS. 2 and 3, hand 12 grasps housing 62 to positioncutting head 25 in the appropriate cutting position and orientation.

In one embodiment of the present invention, a variety of cutting headsmay be coupled to connecting link 58 at pin 60 and coupled to housing62, as depicted in FIG. 4. A variety of cutting implements may beattached to housing 62 and connecting link 58 such as pruner 54, hedgeshears 90, grass shears 92, and other cutting devices. Furthermore, anextension handle 94 may be coupled to housing 62 by coupling connectinglink 58 to a housing link 96. Housing link 96 extends out both ends ofextension handle 94 such that housing link 96 may be coupled toconnecting link 58 on a first end and to the cutting implement such aspruner 54, head shears 90, or grass shears 92, at a second end.

As depicted in FIG. 5A, operator 10 is depicted using foot operatedcutting device 20 having extension handle 94 coupled to housing 62 andto cutting implement 92. As depicted in FIG. 5A, operator 10 is able toeasily reach foliage that is located substantially above the head ofoperator 10, and is able to easily actuate shears 92 by pressing hisheel 45 onto tread 78 of foot actuator 35.

Similarly, as depicted in FIG. 5B, operator 10 is positioned to cutfoliage that is located substantially below the waist of operator 10 byusing foot operated cutting device 20 having extension handle 94attached to housing 96 at a first end and to shears 92 at a second end.As depicted in FIG. 5B, operator 10 does not have to bend over in asubstantial manner in order to cut foliage that is low to the groundbecause extension handle 94 provides the necessary reach and actuationis simplified by providing actuation through heel 45 of operator 10 totread 78 of foot actuator 35.

Referring now to FIG. 7, an alternative embodiment of the presentinvention is depicted. Foot operated cutting device 120 includes acutting head 125 coupled to a housing 162, housing 162 being coupled toa hydraulic cylinder 163, and hydraulic cylinder 163 having a piston165. Piston 165 is coupled to a rod 166, rod 166 being coupled to aconnecting link 158 and connecting link 158 being coupled to a blade152. Blade 152 is pivotally coupled to a jaw 154 at a pin 156. Hydrauliccylinder 163 is fluidly coupled to a hydraulic hose 174. Hydraulic hose174 has a lumen 172 extending therethrough to communicate hydraulicfluid.

A foot actuator 135 has a base 176 and a tread 178 on which a heel 45transmits a force provided by operator 10. A hydraulic cylinder 177 iscoupled to tread 178. A piston 179 rides within hydraulic cylinder 177and is coupled to base 176 by a piston rod 181.

In operation, as heel 45 transmits a force to tread 178, piston 179pressurizes hydraulic fluid 183 that is contained within hydrauliccylinder 177, thereby pushing hydraulic fluid 183 through lumen 172 inhydraulic hose 174 and into hydraulic cylinder 163. As hydraulic fluidis communicated into hydraulic cylinder 163, piston 165 pushes rod 166thereby causing blade 152 to pivot about pin 156 and causing a bight153, that is formed by blade 152 and jaw 154, to close.

Once bight 153 is closed, and heel 45 releases pressure from tread 178,biasing spring 150, which stored potential energy during the closingprocess, presses on housing 162 and on a plate 167 that is coupled torod 167. Therefore, biasing spring 150 causes piston 165 to pressurizefluid 183 through lumen 172 in hydraulic hose 174 and into hydrauliccylinder 177 thereby returning tread 178 to its unactuated position asdepicted in FIG. 7.

Referring now to FIGS. 6A-6C, a foot actuator 235 is depicted. Footactuator 235 is an alternative embodiment of foot actuator 35. Asdepicted in FIG. 6A, foot actuator 235 has a base portion 276 that ispivotally coupled to a tread portion 278. Tread portion 278 is coupledto a cable 272 and base portion 276 is coupled to a sheath 274. Footactuator 235 is configured to be attachable to a shoe 240 by a toe strap242 and a heel strap 244. (In another alternative embodiment, footactuator 235 may be integrated into a special shoe.) Heel strap 244 iscoupled to tread portion 278 and toe strap 242 is coupled to treadportion 278 by a toe strap loop 246.

As depicted in FIG. 6A, foot actuator 235 may be locked into an actuatedposition as shown in FIG. 6A, such that operator 10 would be able towalk with a normal gait having foot actuator 235 attached to shoe 240,foot actuator 235 not substantially interfering with the normal gait ofan operator. Foot actuator 235 is put into a locked or fixed position byoperator 10 positioning a hook 250 to engage a bottom bar 277 of baseportion 276. Operator 10 may position hook 250 into the locked positionby either performing an appropriate foot movement or by placing actuator235 into the locked position by hand. In an alternative embodiment itmay be possible to lock up foot actuator 235 by locking the cuttinghead, such as cutting head 25, in a closed position. As depicted in FIG.6A, having foot actuator 235 in a locked position causes cutting head 25to be locked in the closed position. Locking foot actuator 235 into afixed position is not limited to the hook 250 and bar 277 configurationas depicted in FIGS. 6A-6C, other mechanical configurations may beapplied to perform the locking function.

As depicted in FIG. 6B, when an operator chooses to use cutting device20, hook portion 250 is disengaged from rod 277 such that tread 278 isfree to move relative to base 276, as depicted in FIG. 6C. FIG. 6Cdepicts foot actuator 235 in the non-actuated or near non-actuatedposition, correspondingly a bight such as bight 53 in FIG. 1 would beopen.

It is understood that the above description is of a preferred exemplaryembodiment of the present invention, and that the invention is notlimited to the specific forms described. For example, while theinvention has been described in association with a device taking theform of a pruner, it can be used with other items as well. In addition,the foot actuator, cutting heads, housings, and actuating mechanisms cantake other shapes and forms so long as they can be associated and thatthe housing is configured to support the drive mechanism and cuttingdevice. Nevertheless, it should be understood that these and othersubstitutions, modifications, changes, and omissions may be made in thedesign and arrangement of the elements disclosed herein withoutdeparting from the scope of the appended claims.

What is claimed is:
 1. A cutting device comprising: a cutting head, having a cutter; a foot actuator, having a first hydraulic cylinder coupled thereto and the foot actuator configured to actuate the first hydraulic cylinder; a housing supporting the cutting head and a second hydraulic cylinder, the second hydraulic cylinder being coupled to the cutting head, moveable from a first position to a second position, and configured to actuate the cutter, the housing configured to support a second hydraulic cylinder biasing spring configured to bias the second hydraulic cylinder to one of the first position and the second position; a hydraulic hose coupled to the first hydraulic cylinder on a first end and coupled to the second hydraulic cylinder on a second end, the hydraulic hose communicating hydraulic fluid between the first and second hydraulic cylinders, wherein the foot actuator receives a force input, the force input being transmitted to the first hydraulic cylinder thereby causing hydraulic fluid to flow through the hydraulic hose and causing movement in the second hydraulic cylinder the second hydraulic cylinder transmitting a force to the cutting device.
 2. The cutting device of claim 1 wherein the foot actuator is a pedal, the pedal having a base and a tread pivotally coupled to the base.
 3. The cutting device of claim 1 wherein the type of cutting head is interchangeable.
 4. The cutting device of claim 1 wherein the cutter is a pruner having a blade pivotally coupled to a jaw about a pivot point, the jaw cooperating with the blade to sever a workpiece received in a bight formed by the jaw.
 5. The cutting device of claim 1 wherein the foot actuator is attachable to a shoe.
 6. The cutting device of claim 1 wherein an extension handle is attachable between the housing and the cutting head.
 7. A cutting device comprising: a cutting head, having a cutter; a foot actuator, having a first hydraulic cylinder coupled thereto and the foot actuator configured to actuate the first hydraulic cylinder; a housing supporting the cutting head and a second hydraulic cylinder, the second hydraulic cylinder being coupled to the cutting head and configured to actuate the cutter; a hydraulic hose coupled directly to the first hydraulic cylinder on a first end and coupled directly to the second hydraulic cylinder on a second end, the hydraulic hose communicating hydraulic fluid between the first and second hydraulic cylinders, wherein the foot actuator receives a force input, the force input being transmitted to the first hydraulic cylinder thereby causing hydraulic fluid to flow through the hydraulic hose and causing movement in the second hydraulic cylinder, the second hydraulic cylinder causing a cutting action in the cutter.
 8. The cutting device of claim 7 wherein the foot actuator is a pedal, the pedal having a base and a tread pivotally coupled to the base.
 9. The cutting device of claim 7 wherein the type of cutter is interchangeable.
 10. The cutting device of claim 7 wherein the cutting head is a pruner having a cutter with a blade pivotally coupled to a jaw about a pivot point, the jaw cooperating with the blade to sever a workpiece received in a bight formed by the jaw.
 11. The cutting device of claim 7 wherein the foot actuator is attachable to a shoe.
 12. The cutting device of claim 7 wherein an extension handle is attachable between the housing and the cutting head.
 13. A hydraulically actuated cutting device comprising: a cutting head, having a cutter; an actuator configured to be actuated by the foot of a user, the actuator having a first hydraulic cylinder coupled thereto and the actuator configured to actuate the first hydraulic cylinder; a housing supporting the cutting head and a second hydraulic cylinder, the second hydraulic cylinder being coupled to the cutting head and configured to actuate the cutter; a flexible hydraulic conduit coupled directly to the first hydraulic cylinder on a first end and coupled directly to the second hydraulic cylinder on a second end, the flexible hydraulic conduit communicating hydraulic fluid between the first and second hydraulic cylinders, wherein the actuator receives a force input, the force input being transmitted to the first hydraulic cylinder thereby causing hydraulic fluid to flow through the flexible hydraulic conduit and causing movement in the second hydraulic cylinder, the second hydraulic cylinder causing a cutting action in the cutter.
 14. The cutting device of claim 13 wherein the foot actuator is a pedal, the pedal having a base and a tread pivotally coupled to the base.
 15. The cutting device of claim 13 wherein the type of cutter is interchangeable.
 16. The cutting device of claim 13 wherein the cutting head is a pruner having a blade pivotally coupled to a jaw about a pivot point, the jaw cooperating with the blade to sever a workpiece received in a bight formed by the jaw.
 17. The cutting device of claim 13 wherein the foot actuator is attachable to a shoe.
 18. The cutting device of claim 13 wherein an extension handle is attachable between the housing and the cutting head. 